Answer:
The ratio of electric force to the gravitational force is 
Explanation:
It is given that,
Distance between electron and proton, 
Electric force is given by :

Gravitational force is given by :

Where
is mass of electron, 
is mass of proton, 
is charge on electron, 
is charge on proton, 



So, the ratio of electric force to the gravitational force is
. Hence, this is the required solution.
Hubble space telescope, Hubble deep field guide, moon, mercury, Saturn, sun, galaxy messier 101
The most exact answer is 78.4J also in this kind of options we can say answer "d"
U have to *modify it to increase its ground clearance*